NUMERICAL SOLUTION OF FULL-WAVE EQUATION WITH MODE-COUPLING.

Abstract

A new method for the numerical solution of the wave equation governing the propagation of electromagnetic waves in a horizontally stratified, inhomogeneous, anisotropic layer is described. The wave equation is a homogeneous set of four linear differential equations of the first order. In the computer calculation, all singularities of the wave equation are removed in practical cases and a proper step-size based on the gradients of the medium properties is programmed automatically. The multiplicative nature of the solutions facilitates the procedure. Modification of solutions from one height to another is expressed in explicit form on the assumption that the propagation tensor varies linearly with height in each step of integration. In the mathematical development, matrix operations are extensively used in order to achieve a general representation. Four independent solutions of the wave equation are derived. During an ordinary integration for an inhomogeneous medium, a degradation occurs inevitably in the degree of linear independence among special solutions. This cause is analyzed. To obtain a complete set of special solutions with good linear independence, a particular device is developed for general applications. This method has been programmed for computer calculation by an IBM 7090. The resultant wave fields and wave polarizations for the independent modes are shown for a model ionosphere. The resultant wave is described as a 'scrambling' of four characteristic waves. The 'scrambling' state is visualized at each height. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1966
Accession Number
AD0630612

Entities

People

  • Samuel Horowitz
  • Yuji Inque

Organizations

  • Air Force Cambridge Research Laboratories

Tags

DTIC Thesaurus Topics

  • Computers
  • Couplings
  • Degradation
  • Differential Equations
  • Equations
  • Ionosphere
  • Linear Differential Equations
  • Mathematical Analysis
  • Mathematics
  • Nonlinear Differential Equations
  • Partial Differential Equations
  • Polarization
  • Wave Equations

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Fluid Dynamics.